3071 Background: Disparities in cancer screening and outcomes based on factors such as gender, socioeconomic status, and race/ethnicity are well documented.1 The Circulating Cell-free Genome Atlas study (CCGA; NCT02889978) was designed to develop and validate a blood-based multi-cancer early detection (MCED) test analyzing plasma cell-free DNA (cfDNA) to detect cancer signals across multiple cancer types and simultaneously predict cancer signal origin. Findings stratified by race/ethnicity from the third and final CCGA validation sub-study are reported. Methods: CCGA is a prospective, multicenter, case-control, observational study with longitudinal follow-up (overall N = 15,254). In this pre-specified exploratory analysis from the third substudy, key objectives were to evaluate test performance for cancer signal detection (specificity, overall sensitivity, and sensitivity by clinical stage) among racial/ethnic groups. Plasma cfDNA from evaluable samples was analyzed using a targeted methylation bisulfite sequencing assay and a machine learning approach. Overall, 4077 participants comprised the independent validation set with confirmed status (cancer: n = 2823; non-cancer: n = 1254). The groups stratified by race/ethnicity were White Non-Hispanic, Black Non-Hispanic, Other Non-Hispanic (including but not limited to Asian, Native Hawaiian, Pacific Islander, American Indian, Alaska Native), Hispanic (all races), and Other/unknown. The study was not powered to detect statistical differences between groups. Results: Cancer and non-cancer groups were predominantly White (2316/2823, 82.0% and 996/1254, 79.4%, respectively). Across racial/ethnic groups, specificity for cancer signal detection was 99.6% (White Non-Hispanic: 992/996, 95% confidence interval [99.0-99.8%]), 100.0% (Black Non-Hispanic: 85/85 [95.7-100.0%]), 100.0% (Other Non-Hispanic: 33/33 [89.6-100.0%]), 98.1% (Hispanic: 101/103 [93.2-99.5%]), and 100% (Other/unknown: 37/37 [90.6-100.0%]). Despite slight differences in cancer type and staging across racial/ethnic groups, overall sensitivity for cancer signal detection among groups ranged from 43.9% to 63.0% (White Non-Hispanic: 50.5%, 1169/2316 [48.4-52.5%], Black Non-Hispanic: 53.9%, 104/193 [46.8-60.8%], Other Non-Hispanic: 43.9%, 25/57 [31.8-56.7%], Hispanic: 63.0%, 121/192 [56.0-69.5%], and Other/unknown: 52.3%, 34/65 [40.4-64.0%]). For all racial/ethnic groups, sensitivity generally increased with clinical stage (with limited exceptions at Stage IV in some groups with small sample sizes). Conclusions: The MCED test demonstrated consistent specificity and sensitivity across racial/ethnic groups, though results are limited by sample size for some groups. These findings indicate broad applicability and support clinical implementation of this MCED test on a population scale. 1. Zavela et al. Brit J Cancer 2021. Clinical trial information: NCT02889978.
ATRT-04. CORRELATION OF CLINICOPATHOLOGIC FEATURES AND CUMULATIVE INCIDENCE OF RELAPSE FOR PATIENTS WITH ATYPICAL TERATOID RHABDOID TUMOR ON ACNS0333: A REPORT FROM THE CHILDREN’S ONCOLOGY GROUP
Abstract Purpose Intensive multi-modal regimens have improved survival for patients with atypical teratoid rhabdoid tumor, however relapse rates remain high. A better understanding of clinical and pathologic features associated with tumor relapse is critical to risk-stratifying patients. Patients and Methods ACNS0333 treatment consisted of multi-agent chemotherapy, high-dose chemotherapy, and radiation therapy, lasting approximately 6 months. Variables including patient age, sex, tumor location, M-stage, degree of resection, order of therapy, germline status, and molecular subgroup were analyzed. Cumulative incidence (CI) of event free survival due to relapse was evaluated for each variable. Results Thirty-three of 65 evaluable patients had tumor relapse. For the entire cohort, the CI of relapse was 21.8% at 6 months, 40.6% at one year and 50.3% at 4 years. For patients with infratentorial tumors, CI of relapse was 26.3%, 34.2% and 37.2%, at 6 months, 1 and 4 years respectfully compared to 15.3%, 49.9%, and 69.7% for those with supratentorial tumors (p 0.051). Patients with SHH subtype had no relapses in the first 6 months and CI of relapse of 37.5% at 4 years, while those with TYR and MYC subgroups had CI of relapse of 33.3% and 26.7% at 6 months and 46.3% and 73.3% at 4 years respectfully (p 0.088). Patients with germline mutations had a cumulative incidence of relapse of 20% at 6 months and 60% at 12 months compared to 22.6% and 37.7% respectfully for those without. No obvious trends were noted based on other analyzed variables. Conclusions ACNS0333 was not powered to determine prognostic indicators of relapse, however, this data suggest interesting trends based on tumor location, subtype and germline status. Infratentorial location and SHH subtype maybe associated with lower risk of relapse. Larger data sets must be compiled to further investigate these variables, perform multivariate analyses and inform risk-stratification on future trials.
OP02 Ustekinumab versus adalimumab for induction and maintenance therapy in Moderate-to-Severe Crohn’s Disease: The SEAVUE study
Abstract Background We studied the efficacy and safety of ustekinumab (UST) vs adalimumab (ADA) through 1 year in biologic-naïve patients (pts) with moderate-to-severe Crohn’s disease. Methods SEAVUE was a multicenter, randomized, blinded, parallel-group, active-controlled study in adults with CD Activity Index (CDAI) scores ≥220/≤450. Biologic-naïve pts failing/intolerant to conventional therapy with any size ulcer on baseline (BL) ileocolonoscopy were eligible. Pts were randomized 1:1 to UST (⁓6mg/kg IV at BL then 90mg SC every 8 weeks [Ws]) or ADA (160/80mg SC at BL/W2, then 40mg SC every 2 Ws) per US-approved regimens (no dose modifications). Primary endpoint was clinical remission at W52 (CDAI <150). Major secondary endpoints were corticosteroid-free remission, clinical response (≥100-point CDAI decrease from BL), remission in pt-reported CDAI components (PRO-2 symptom remission: abdominal pain mean daily score ≤1 and stool frequency mean daily score ≤3), and endoscopic remission (SES-CD score ≤3/0 for pts with BL score=3) at W52 and clinical remission at W16. Results 386 pts were randomized to UST or ADA. BL demographics and disease characteristics were balanced between groups and indicative of pts with early, moderate-to-severe CD (median CD duration, 2.58 years; CDAI, 289.5; SES-CD, 8.0). At W52, 65% of UST-treated and 61% of ADA-treated pts achieved clinical remission (Δ=4.0%; 95% CI, -5.5%, 13.5%; p=0.417). Major secondary endpoints, including endoscopic remission, were similar between groups (Table 1), as were remission rates at assessment points through W52. Some other secondary endpoints showed numerical (not statistical) differences between UST and ADA (Table 1). Key safety events are summarized in Table 2. Among UST-treated and ADA-treated pts, 34.0% and 40.5% had infections, 2.6% and 7.2% had serious adverse events (AEs) of worsening CD, and 6.3% and 11.3% had AEs that led to discontinuation (DC) of study drug, respectively. One ADA-treated pt had active pulmonary TB. Injection-site reactions associated with active treatment occurred in 1.0% of UST-treated and 10.3% of ADA-treated pts. Overall, 15.2% of UST-treated and 23.6% of ADA-treated pts DC before W52. Reasons for DC were primarily lack of efficacy (UST, 2.1% vs ADA, 5.1%), AEs (UST, 5.7% vs ADA, 10.7%), and withdrawal of consent (UST, 5.8% vs ADA, 5.1%). Time to treatment DC was longer with UST vs ADA (post hoc analysis). Conclusion Both UST and ADA were highly effective in this population of biologic-naïve pts. Rates of clinical remission at W52 were not statistically significantly different between treatment groups. DC rates were numerically lower for UST. Safety results were consistent with prior experience for both treatments.
Abstract 13594: Adverse Right Ventricular Remodelling, Function and Stress Responses in Obesity: Implications for Severe Acute Respiratory Illness
Introduction: The mechanisms linking obesity to increased mortality in patients with coronavirus-disease 2019 (COVID-19) are unclear. Hypothesis: We hypothesised that obesity would be associated with adverse right ventricular (RV) remodelling and function which might be further exacerbated by COVID-19 associated increases in RV afterload/demand. Methods: We used echocardiography and computed tomography to establish links between RV dimensions and function and bodyweight in patients with severe COVID-19. In obese and non-obese participants without COVID-19, we used cardiovascular magnetic resonance to define the effects of obesity upon RV volumes, energetics, systolic function and stress reserve. Results: In patients with severe COVID-19, increasing bodyweight was associated with disproportionate RV dilatation (n=26, echocardiography, R=0.42, P=0.03, CT n=34, R=0.23, P=0.004) and impairment of RV systolic function (fractional area change (FAC) R=-0.45, P=0.04); obesity (BMI >30kg/m2) was associated with a 32% reduction in RV FAC (P=0.03). Similar associations were seen in a validation cohort (n=91, all P<0.05). In participants without COVID-19, class III obesity (n=54, BMI 47±4 kg/m 2 ) was associated with RV remodelling, impaired cardiac energetics (PCr/ATP ratio 23% lower, P<0.001) and reduction in RV systolic function at rest (by 3±1%, P=0.01), which was related to reduced energetics (R=0.3, P=0.04). Participants with class I-II obesity (BMI 35±5 kg/m 2 , n=27) had impaired RV diastolic filling rate at rest (P<0.001) and blunted RV dobutamine stress systolic response (by 68%, P=0.03) and diastolic response (by 78%, P=0.008). Surgical weight loss in patients obesity (n=37, 34±15kg weight loss) was associated with improvement in RV volume (12±26 ml lower, P=0.006) and function (ejection fraction 2±5% higher, P=0.03). Conclusions: Increasing body weight is associated with both significant alterations in RV volumes, systolic function and stress responses which are mitigated with weight loss and also with disproportionate RV dilatation and dysfunction in severe COVID-19. RV dysfunction is a modifiable mechanism which might link obesity to adverse outcomes in patients with COVID-19 and other disorders stressing the right heart.
DNA Methylation Markers for Detection of Cholangiocarcinoma: Discovery, Validation, and Clinical Testing in Biliary Brushings and Plasma
Cholangiocarcinoma (CCA) has poor prognosis due to late‐stage, symptomatic presentation. Altered DNA methylation markers may improve diagnosis of CCA. Reduced‐representation bisulfite sequencing was performed on DNA extracted from frozen CCA tissues and matched to adjacent benign biliary epithelia or liver parenchyma. Methylated DNA markers (MDMs) identified from sequenced differentially methylated regions were selected for biological validation on DNA from independent formalin‐fixed, paraffin‐embedded CCA tumors and adjacent hepatobiliary control tissues using methylation‐specific polymerase chain reaction. Selected MDMs were then blindly assayed on DNA extracted from independent archival biliary brushing specimens, including 12 perihilar cholangiocarcinoma, 4 distal cholangiocarcinoma cases, and 18 controls. Next, MDMs were blindly assayed on plasma DNA from patients with extrahepatic CCA (eCCA), including 54 perihilar CCA and 5 distal CCA cases and 95 healthy and 22 primary sclerosing cholangitis controls, balanced for age and sex. From more than 3,600 MDMs discovered in frozen tissues, 39 were tested in independent samples. In the clinical pilot of 16 MDMs on cytology brushings, methylated EMX1 (empty spiracles homeobox 1) had an area under the curve (AUC) of 0.98 (95% confidence interval [CI], 0.95‐1.0). In the clinical pilot on plasma, a cross‐validated recursive partitioning tree prediction model from nine MDMs was accurate for de novo eCCA (AUC, 0.88 [0.81‐0.95]) but not for primary sclerosing cholangitis–associated eCCA (AUC, 0.54 [0.35‐0.73]). Conclusion : Next‐generation DNA sequencing yielded highly discriminant methylation markers for CCA. Confirmation of these findings in independent tissues, cytology brushings, and plasma supports further development of DNA methylation to augment diagnosis of CCA.
Mucoepidermoid carcinoma of the parotid gland: Twenty‐year experience in treatment and outcomes
AbstractBackgroundParotid gland mucoepidermoid carcinoma (MEC) has published five‐year cancer‐specific survival (CSS) rates of 77%–97%, with variance related to grade.MethodsPatients receiving primary surgery for parotid gland MEC from 1995 to 2014 at a tertiary medical center underwent clinical review, histopathologic review, and cytogenetic analysis. Survival outcomes were evaluated.ResultsAmong 58 patients, T/N/M classification was as follows: T1 in 35 patients, T2 in 14, T4a in 9, N0 in 53, N1 in 2, N2b in 3. Histologic grade was low in 27, intermediate in 17, and high in 12 patients with 98% MAML2 positivity. All patients underwent parotidectomy, and seven patients received adjuvant radiation therapy. CSS was 100% at 5 years and 94.1% at 10 and 15 years. Two patients experienced locoregional recurrence.ConclusionsTreatment with adequate surgical resection and adjuvant radiation therapy for high‐grade or advanced‐stage tumors yields excellent survival, independent of clinical stage or pathologic grade.
AbstractObjectivesInhibitors to the checkpoint proteins cytotoxic T‐lymphocyte‐associated protein 4 (CTLA‐4) and programmed cell death protein 1 (PD‐1) are becoming widely used in cancer treatment. However, a lack of understanding of the patient response to treatment limits accurate identification of potential responders to immunotherapy.MethodsIn this study, we assessed the expression of PD‐1 and CTLA‐4 on 19 leucocyte populations in the peripheral blood of 74 cancer patients. A reference data set for PD‐1 and CTLA‐4 was established for 40 healthy volunteers to determine the normal expression patterns for these checkpoint proteins.ResultsUnsupervised hierarchical clustering found four immune profiles shared across the solid tumor types, while chronic lymphocytic leukaemia patients had an immune profile largely unique to them. Furthermore, we measured these leucocyte populations on an additional cohort of 16 cancer patients receiving the PD‐1 inhibitor pembrolizumab in order to identify differences between responders and non‐responders, as well as compared to healthy volunteers (n = 20). We observed that cancer patients had pre‐treatment PD‐1 and CTLA‐4 expression on their leucocyte populations at different levels compared to healthy volunteers and identified two leucocyte populations positive for CTLA‐4 that had not been previously described. We found higher levels of PD‐1+ CD3+ CD4− CD8− cells in patients with progressive disease and have identified it as a potential biomarker of response, as well as identifying other significant differences in phenotypes between responders and non‐responders.ConclusionThese results are suggestive that categorisation of patients based on immune profiles may differentiate responders from non‐responders to immunotherapy for solid tumors.
Clinical Characteristics, Outcomes, Disposition, and Acute Care of Children and Adolescents Treated for Acetaminophen Toxicity